Iterator Next Not Working In If
Apr 4, 2014
I need to find out if one array list is a sub-sequence of another. The elements in the first list all need to be in the second list and must be in the same order. So s1<n, t, a> is a sub-sequence of s2<q, n, f, r, t, d, a>, but s1<a, a, t> is not a sub-sequence of s2<a, t, a>. I need to use iterators to go through each list, and I should only go through each list once (since it has to be in the same order) so nested loops don't seem like they would work because it would start at the beginning of one list every time it moved to another element in the outer loop's list.I seem to have an issue where the itr1. next()
is ignored when in an if statement.
My current code just stalls and will never stop running. I've also switched things around and put the not equal check after the if it is equal and it throws a NoSuchElementException.
import dataStructures.*;
public class Subsequence3
{
public static void main(String[] args)
{
ArrayList<Character> s1 = new ArrayList<Character>();
s1.add('n');
s1.add('p');
s1.add('a');
[code]....
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Nov 12, 2014
I am trying to add the contents of the iterator to an arraylist so I can do other stuff to it, however I am getting an error when I actually try adding it to the list, stating that
"The method add(Map.Entry<String,myObject>) in the type ArrayList<Map.Entry<String,myObject>> is not applicable for the arguments (myObject)"
Here is what I have tried doing:
Iterator<Map.Entry<String, myObject>> iterator = hash.entrySet().iterator();//hash is my HashMap object
ArrayList<Map.Entry<String, myObject>> list = new ArrayList<Map.Entry<String, myObject>>();
while(iterator.hasNext()){
Map.Entry<String, myObject> entry = iterator.next();
list.add(entry.getValue());//error here
}
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Mar 25, 2015
I am trying to use an iterator instead of a foreach loop to go through a list of inventories to see if a car is rearDrive and count how many are rearDrive but somehow I seem to be missing something that the counter isn't working as expected.
public int howManyAreRearWheelDrive(){
int i = 0;
int counter = 0;
int inventSize = inventory.size()-1;
while(i < inventSize){
boolean wheelDrive = inventory.get(i).getIsRearWheelDrive();
if( wheelDrive == true){
counter++;
}
}
return counter; // returning here doesn't give me anything
}
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Feb 24, 2014
The Iteratior provides the functionality of traversing and removal which we can achieve through normal for loop and remove() of the data structure.Then, why do we need Iterator explicitly and as an inner class?
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Mar 3, 2014
What does the iterator() method return???it can't return an object of Iterator as it's an interface...
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Feb 8, 2015
As part of a homework assignment in my 1st Java Class, I am creating my own Circular Generic LinkedList and Array class. My class uses the Queue Interface Extends Iterable but I am creating my own methods to work with. For the most part, I believe I have been successful in creating the class aside from one method. That method is the Iterator<E> iterator().
/**
* Return a fail-fast iterator, which throw a java.util.ConcurrentModificationException
* if the client modifies the collection (via enqueue(...) or dequeue()) during iteration.
*/
@Override
public Iterator<E> iterator() {
I don't understand how an iterator, let alone a "fail-fast" iterator ties into my project. I've spent hours reading up on a way to imploy my own generic fail-fast iterator but to no avail.
I feel like I could come up with some workable code if I knew what the point is to useing a user-defined, non Java Library iterator is to do.
As well, does throwing a ConcurrentModificationException require a try and catch block?
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May 3, 2014
I have a problem with a linked list iterator, my problem is implementing the iterator.remove method given the following code:
package mapsql.util;
import java.util.Iterator;
public class LinkedList<T> implements List<T> {
private class Node implements Position<T> {
T element;
Node next, prev;
public Node(T element) {
this.element = element;
[Code] ....
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Mar 12, 2015
I am tring to run LDA to generate some topics from txt files as the following one:
Document1 label1 forest=3.4 tree=5 wood=2.85 hammer=1 colour=1 leaf=1.5
Document2 label2 forest=10 tree=5 wood=2.75 hammer=1 colour=4 leaf=1
Document3 label3 forest=19 tree=0.90 wood=2 hammer=2 colour=9 leaf=4.3
Document4 label4 forest=4 tree=5 wood=10 hammer=1 colour=6 leaf=3
Each numeric value in the file is an indication of the number of occurrences of each feature (e.g., forest, tree) multiplied by a given penalty. To generate instances from such a file, I use the following Java code:
String lineRegex = "^(S*)[s,]*(S*)[s,]*(.*)$";
String dataRegex = "[p{L}([0-9]*.[0-9]+|[0-9]+)_=]+";
InstanceList generateInstances(String dataPath) throws UnsupportedEncodingException, FileNotFoundException {
ArrayList<Pipe> pipeList = new ArrayList<Pipe>();
pipeList.add(new Target2Label());
[Code] .....
I then add the so-generated instances to my model using the instruction model.addInstances(generatedInstances). The resulting output is described below.
It contains errors caused by the instruction model.addInstances(generatedInstances). Debugging my code showed me that the alphabet associated to the model is null. Am I using the wrong iterator?
name: document1
target: label1
input: TokenSequence [forest=3.4 feature(forest)=3.4 span[0..10], tree=5 feature(tree)=5.0 span[11..17], wood=2.85 feature(wood)=2.85 span[18..27], hammer=1 feature(hammer)=1.0 span[28..36], colour=1 feature(colour)=1.0 span[37..45], leaf=1.5 feature(leaf)=1.5 span[46..54]]
Token#0:forest=3.4 feature(forest)=3.4 span[0..10]
[Code] ....
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Feb 17, 2015
I have the following HashMap:
// 2009
nobelPrizeWinners.put("2009 Physics",
new PrizeWinner[] {new PrizeWinner("Charles K.", "Kao"),
new PrizeWinner("Willard S.", "Boyle"), new PrizeWinner("George S.", "Smith")});
nobelPrizeWinners.put("2009 Chemistry",
new PrizeWinner[] {new PrizeWinner("Venkatraman", "Ramakrishnan"),
[Code] .....
At the moment, my output is:
2008: Chemistry: Osamu Shimomura, Martin Chalfie, Roger Y. Tsien
2008: Economics: Paul Krugman
2008: Literature: Jean-Marie Gustave Le Clézio
2008: Medicine: Harald zur Hausen, Françoise Barré-Sinoussi, Luc Montagnier
2008: Peace: Martti Ahtisaari
[Code] .....
However, I need a blank line between the final entry of 2008 and the first entry of 2009.
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Oct 14, 2014
My homework is a Double Circular Link list and when i write implements Iterator it gives me a an error when I compile it the same for my subset method...
ERRORS :DoublyCircularList.java:55: error: DoublyCircularList.iterator is not abstract and does not override abstract method remove() in Iterator public class iterator implements Iterator<T>
^
Note: DoublyCircularList.java uses unchecked or unsafe operations.
Note: Recompile with -Xlint:unchecked for details.
1 error
import java.util.Iterator;
public class DoublyCircularList<T extends Comparable<T>> extends LinkedList<T>implements Iterable<T>
{
Node<T> first;
int size;
public DoublyCircularList(){
first = null;
size = 0;
[code]....
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Nov 5, 2014
List<Integer> list = new ArrayList<Integer>();
for (int i = 0; i < 5; i++) {
list.add(i * 3);
}
ListIterator<Integer> listItr = list.listIterator();
System.out.println("Traversing in a forward direction");
[Code] ....
Output:--
Traversing in a forward direction
0 3 6 9 12
Traversing in a backward direction
12 9 6 3 0 425
Why 425 is not showing when we are traversing in a forward direction.
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Sep 23, 2014
I'm not new to java but i'm not able to solve the following issue: I have a class
public class Localizzazioni implements java.io.Serializable {
private <complexType> id;
public getId().......
public setId().....
The complexType is a class defined in the code somewhere. Now I want to access it in another class I have
Set localizzazioni = new HashSet(0);
localizzazioni=opere.getOiLocalizzazioneOperas(); -- this object give an object of tyoe HashSet
for(Object object : localizzazioni) {
object.get......... // i cannot use any method defined in the class Localizzazioni
}
Why I cannot write inside the for object.getId() and using it?? In other word how i can access the element contained in the object?? the object is an iterator of type Localizzazioni . The class Localizzazioni has some method but i cannot use them? why ....
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Apr 14, 2015
I have been researching the Iterator and making a class implement iterable. I have seen this example shown below and was wondering how I could change this so that iterable() is not called upon in the main. I would like to be able to make a method that returns an instance of a class that implements the Iterator interface hopefully an inner class. This is because my program will not have a main and will be supplied with a main that includes a new Object with will use the iterator method.
import java.util.*;
public class IteratorDemo {
public static void main(String args[]) {
// Create an array list
ArrayList al = new ArrayList();
// add elements to the array list
al.add("C");
[Code] ....
This is all I have been able to understand from what I want to do. This does not work and this is what I am trying to achieve
public class MyArrayList implements Iterable {
public static final int DEFAULT_SIZE = 5;
public static final int EXPANSION = 5;
private int capacity;
private int size;
private Object[] items;
[Code] ...
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Apr 10, 2014
I am developing an application to share my client screen with server, it is working well on swing. But i want to develop as web application, i am trying to using applet. But i am facing the fallowing problem..,
1) The Applet screen also open and project also running well on server mechine. But unable to see the client screen on the server.
2) The problem may be to display the JDesktopPane or JInternalFrame.
My working Server Code extends withe JFrame..Java Code:
package remoteserver;
import java.awt.BorderLayout;
import java.awt.Container;
import java.io.IOException;
import java.net.ServerSocket;
import java.net.Socket;
import javax.swing.JApplet;
import javax.swing.JDesktopPane;
import javax.swing.JFrame;
import javax.swing.JOptionPane;
[code]....
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Aug 29, 2014
Why in my program keys are not working, what I forgot to write?
import javax.swing.JFrame;
public class Main {
public static void main(String args[]) {
JFrame frame = new JFrame("Stickman");
frame.setDefaultCloseOperation(frame.EXIT_ON_CLOSE);
frame.setSize(450, 490);
[code]....
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Mar 5, 2014
I got my code into a jar, but when I run it I get his message:I just used Eclipse to make my jar and I thought I did it right but I guess not.
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Apr 24, 2014
I wrote a piece of code:
for(int i = 0; i < x; i++){
System.out.println("Enter students full name:");
sName[i] = result.fullName(sc.nextLine());
sExam[i] = result.examName("VB");
System.out.println("Enter students exam score:");
int scor = sc.nextInt();
sScore[i] = result.examScore(scor);
sGrade[i] = result.examGrade(scor);
}
When i run it i get:
Enter number of students:
1
Enter students full name:
Enter students exam score:
The problem is, i cant enter "full name", program is just jumping to the next step "exam score".
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Oct 9, 2014
I am working on a fairly simple program where I have a colour change three times using the red green blue spectrum. The problem is that I keep getting a result of zero no matter what I do.
import java.awt.*;
class RectangleMain
{
public static void main (String[] args) {
ColouredRectangle blocky = new ColouredRectangle(50, 100, 20, 40, Color.red);
System.out.println(blocky.getColour());
blocky.mixColour(Color.blue);
[code]...
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May 31, 2014
I'm programming a game, but the keyListener doesn't work. Here is the source code:
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
public class InputHandler implements KeyListener{
public InputHandler(Game game) {
game.addKeyListener(this);
[code]....
My Question is: Why will it not say "up", if I press "w"?
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May 5, 2014
I'm having a problem where an if statement isn't working. In the Person class boolean olderThan ignores my if statement so it always returns false and I just don't get why that's happening.
import java.util.Calendar;
public class Person {
private String name;
private MyDate birthday;
public Person(String name, int pp, int kk, int vv) {
this.name = name;
[code].....
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Feb 25, 2015
I have added a Simple Jar file in Eclipse Proect->BuildPath->jar file but class Inside that are not showing in My project this is my Project Structure and I have all ready checked in Order and Export..But jar file is not working.
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Sep 7, 2014
I am learning out design patterns and doing a little fun project on Model Control View (MCV). I got the concept down, it is pretty simple for the most part. However my buttons are not working.
Here is the code:
public class Controller
{
private Model model;
private View view;
Controller(Model model, View view) {
this.model = model;
this.view = view;
[code]....
It runs but nothing. My other questions is how can I make a box that will print the results.
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Feb 2, 2014
the problem which im facing when executing jar file is it is not working same as when i run file using the IDE.When run jar file, it won't open the new frame even the user and pass combination correct.But when i'm compiling using the IDE, it works as charm. The main menu popped up after i logged in.I've tried Clean and Build and it's not working too.
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Oct 14, 2014
I code a program using Eclipse Keppler with Java 8.0. I made a program with 2 JPanel. The first JPanel is working well. From a button in first JPanel, I excute second JPanel, but It is not working. No error when I compile the code. Here is, I attached the source code.
import javax.swing.*;
import java.awt.Color;
import java.awt.event.*;
[code]....
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Oct 29, 2014
working on a project but cant seem to get my while loop to restart i want to restart this guessing game if the user inputs y at the end otherwise it will end.
import java.util.Scanner;
import java.util.Random;
public class GuessingGame{
public static void main(String[] args){
Scanner in = new Scanner(System.in);
String again = "y";
while(again=="y"){
[code]....
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May 5, 2015
i am trying to make taxi meter which shows the current price.Rightnow I have to click startmeter afterevery 1 minute than it's update the new price but I want it to update automatically once the price change after 1 minute instead of me pressing startmeter everytime.This is my 1st time I am using timer class. I am not sure why timer is not working.
import java.awt.*;
import java.awt.event.*;
import java.util.Calendar;
import java.util.GregorianCalendar;
import javax.swing.*;
import javax.swing.border.*;
import javax.swing.event.*;
import java.awt.event.ActionListener;
import javax.swing.Timer;
import java.awt.event.*;
[code]....
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